1. Field of the Invention
The invention relates to an arrangement at the discharge end of a debarking machine intended for the preliminary debarking of logs prior to a separately performed final barking, and more particularly to an arrangement at the discharge end which incorporates a conveyor for facilitating and regulating the discharge of logs from the debarking machine.
2. Description of the Related Art
Related debarking machines are described in U.S. Pat. Nos. 4,685,498 and 5,394,912. In these and other known debarking machines, the discharge end is usually provided with a fixed threshold or a vertically adjustable discharge gate for regulating the discharge of logs from the debarking machine. The discharge gate and the fixed threshold impede free movement of logs in the rolling direction of logs, which results in needless rounding of log ends and frequent snapping of logs. The discharge gate and the fixed threshold are also likely to cause obstructions and capacity fluctuations in a debarking machine. In addition, the discharge gate and threshold must be generally followed by a distinct drop, which increases the height of an entire assembly.
To eliminate these drawbacks, in accordance with the present invention the discharge end of a debarking machine is provided with an extension continuing from a lower level of a chute defined by the support surfaces of the debarking machine. The extension is used for bearing and guiding the logs discharging out of the debarking machine.
To promote reliable operation of a debarking machine it is important that, in terms of its orientation and shape, the support surface of the extension be such that it allows a free movement for logs downstream of the debarking machine. In one preferred embodiment of the invention, this is accomplished by arranging the support surface of the extension to be at least roughly parallel to the direction of log movement through the debarking machine. The extension may be configured as a solid support surface adapted only to guide logs discharging from the debarking machine. In such a configuration, the extension has little or no role in controlling the operation of a debarking machine.
However, in preferred embodiments of the invention, wherein the extension is provided with a conveyor or the extension is constituted by a conveyor, the extension also performs a significant function in controlling the debarking machine. This control function becomes particularly conspicuous when the conveyor is adapted to be variable in terms of its speed. At its simplest, the control of discharge rate can be a mere switch for switching the conveyor on or off. Thus, the conveyor can be used for regulating the operation of a debarking machine by discouraging or encouraging the discharge of logs. This is a way of influencing the rate of log admission into the debarking machine and the dwell time of logs in the debarking machine.
In yet another preferred application of the invention, the arrangement is such that the support surface of the extension has a cross-sectional width that is substantially equal to the width of the chute adjacent the extension.
A debarking machine in accordance with the present invention may also be described as a debarking station in the path of a wood flow. Wood support surfaces extend above the discharge conveyor to form a discharge chute for supporting logs being discharged from the debarking station. The discharge chute and the debarking station have a similar cross-sectional shape and are aligned such that logs leaving the debarking station are longitudinally aligned with the discharge conveyor. The arrangement at the discharge end of a debarking machine helps move logs through the debarking station in a controlled manner.